A single extra pound may not sound like a lot, but when you consider that the average adult American gains one
extra pound per year, it becomes clear why middle-age spread is so insidious and common. By the time you're 45,
you're likely to be 20 pounds heavier than when you were 25 -- and 40 pounds bulkier by age 65!

Fortunately, middle-age spread is not inevitable and can, in fact, be prevented, according to a new Harvard study.
After following 120,877 men and women for 20 years, "we found that small dietary and lifestyle changes together
made a big difference -- for bad or good," says Dr. Dariush Mozaffarian, lead author of the study and an associate
professor of medicine and epidemiology at Brigham and Women's Hospital, Harvard Medical School and Harvard School
of Public Health.

What's more, Mozaffarian and his team were able to pinpoint the biggest culprits behind gradual, long-term
weight gain. "Simply trying to eat â€˜everything in moderation' with a focus only on total calories doesn't work,"
says Mozaffarian. What does?

1. Limit starches, sugary drinks, red meat and processed meats.

In the study, the foods associated with the greatest weight gain were:

- Potatoes (in any form, but especially potato chips and French fries)

- Sugar-sweetened beverages

- Red meat

- Processed meats, such as bacon, hot dogs, deli meats, etc.

"Potato intake should be moderated, but focusing on potatoes alone misses the larger point about overall
carbohydrate quality," adds Mozaffarian. "Starches (like potatoes) and refined carbohydrates (such as white bread,
white rice, low-fiber breakfast cereal and many packaged and processed foods) may have similar -- if not identical
-- metabolic effects," he explains. Eating these foods produces the same bursts in blood glucose and insulin levels
as eating refined sugar. These bursts in glucose and insulin increase hunger and, hence, the total amount of food
(and calories) consumed at the next meal.

2. Eat more minimally processed foods.

Not only did these foods seem to curb middle-age spread, but "eating more of these specific foods was actually
associated with relative weight loss," says Mozaffarian. "This indicates that the path to eating fewer calories is
not to simply count calories, but to focus on consuming a more healthy diet in general." Foods you should eat more
of include:

- Vegetables

- Whole grains

- Fruits

- Nuts

- Yogurt

3. Move your body.

Couch potatoes gained noticeably more weight than people who were physically active.

4. Watch those z's.

People who slept six to eight hours a night put on fewer pounds than those who slept fewer than six hours or more than eight.

5. Turn off the TV.

Every hour of TV watched per day increased the number of extra pounds put on over the years.

6. Go easy on the alcohol.

The more alcohol a person drank, the more likely they were to experience middle-age spread.

So if you're feeling nostalgic for the numbers that appeared when your 20-year-old body stepped on the scale --
and if you want to keep those numbers from climbing -- "eat more minimally processed foods and fewer starches and
refined foods," advises Mozaffarian. And don't forget to "be active, turn off the TV and get enough (but not too
much) sleep" as well.

Nancy Gottesman was a senior
editor at Shape
magazine for 11 years. Since going freelance, she's been
writing on health and nutrition for publications such as Ladies' Home
Journal; O, The Oprah Magazine; Parents; Fit Pregnancy; and Viv.